I have the Nils chukka and the Genet chukka, and I find that the fit is very similar, if not identical. I went down half a size in both. I wear US 9.5/UK 8.5 and I have them in size 9. There is a little room in the front, but I think that is as it is meant to be. I like both very much, although I am having the Genet re-soled in Dainite.